Photographic processes and elements

ABSTRACT

PROCESSES FOR PROVIDING PHOTOGRAPHIC REPRODUCTIONS WHEREIN SILVER NEGATIVE IMAGES ARE DEVELOPED IN IMAGEWISE EXPOSED PHOTOGRAPHIC ELEMENTS HAVING AT LEAST TWO SUPERPOSED HYDROPHILIC COLLOID EMULSION IMAGE RECORDING LAYERS CONTAINING SILVER HALIDE AND COLOR FORMING COUPLERS WHERIN AT LEAST ONE OF THE SILVER HALIDE EMULSION IMAGE RECORDING LAYERS CONTAINS FROM ABOUT 0.5 TO 10 MOLE PERCENT IODIDE, BASED ON THE TOTAL AMOUNT OF HALIDE IN THE EMULSION LAYER. DEVELOPMENT OF THE IMAGEWISE EXPOSED NEGATIVE PHOTOGRAPHIC ELEMENTS IN A PHOTOGRAPHIC COLOR DEVELOPER CONTAINING SILVER HALIDE SOLVENT AND REMOVAL OF SILVER AND SILVER HALIDE FROM SAID NEGATIVE ELEMENTS RESULT IN COLOR NEGATIVES HAVING IMPROVED INTERMIAGE CHARACTERISTICS.

United States Patent 3,832,174 PHOTOGRAPHIC PROCESSES AND ELEMENTSHohson Joseph Bello, Jr., and Albert Charles Smith, Jr.,

Rochester, N.Y., assignors to Eastman Kodak Company, Rochester, N .Y. NoDrawing. Filed June 7, 1972, Ser. No. 260,617 Int. Cl. G03c 7/16, 7/32,7/40 US. Cl. 96-22 Claims ABSTRACT OF THE DISCLOSURE Processes forproviding photographic reproductions wherein silver negative images aredeveloped in imagewise exposed photographic elements having at least twosuperposed hydrophilic colloid emulsion image recording layerscontaining silver halide and color forming couplers wherein at least oneof the silver halide emulsion image recording layers contains from about0.5 to 10 mole percent iodide, based on the total amount of halide inthe emulsion layer. Development of the irnagewise exposed negativephotographic elements in a photographic color developer containing asilver halide solvent and removal of silver and silver halide from saidnegative elements result in color negatives having improved interimagecharacteristics.

The present invention relates to photographic processes, and moreparticularly to photographic processes for providing multicolor negativereproductions having improved interlayer interimage effects.

The dyes obtained in multicolor photographic reproductions are notalways true colors. For example, magenta dyes often have small amountsof blue light absorption and red light absorption. Likewise, yellow dyesand cyan dyes absorb small amounts of light other than blue andred-light, respectively. The effects of such unwanted absorptions is theproduction of dark and desaturated colors or color hue errors.

Such deficiencies in dyes obtained in multicolor photographic processescan be compensated, at least in part, by creating certain interimageefiects. Interirnage eflects can have significant influences on thecolor reproduction by giving partial or complete correction for theunwanted light absorptions by dyes used in photographic materials.

Interimage effects are Well known in photographic multicolor processes.See, for example, Hanson and Horton, Journal of the Optical Society ofAmerica, vol. 42, No. 9 pages 663-669, September 1952 and PinneyInterimage Effects and Color Reproduction, the SPSE Reporter, November1960. It is Well known that under certain development conditions thedegree of development in one layer may be influenced by an adjacentdeveloping layer. When this occurs in a multilayer negative element, thefinal dye content of the adjacent layer is a function of the developmentoccurring in both layers. Such effects have been referred to asinterlayer interimage effects.

Although interlayer interimage effects may be present in many developed,multilayer negative images they generally are too small to be ofpractical importance. This is especially true of many negative elementswhich receive direct color development.

In accordance with this invention novel means are provided for inducinginterlayer interimage effects in elements for providing multicolornegative photographic reproductions.

It is, therefore, one object of this invention to provide 'a novelmethod for correcting for unwanted light absorptions by dye imagesformed in photographic multicolor negative processes.

It is another object of this invention to provide a novel tographicmulticolor reproductions.

mice

These and other objects of this invention are accom-- plished byprocessing a silver halide negative multilayer color photographicelement, wherein at least one of the silver halide emulsion imageforming layers contains from about 0.510 mole percent iodide as mixedsilver halide and at least one of the silver halide emulsion imageforming layers is essentially iodide free, in a color developer solutioncontaining a silver halide solvent followed by removal of residualsilver and silver halide.

The interlayer interimage eflfects manifest themselves in such improvedproperties as brighter and more saturated colors prepared from suchphotographic elements.

Best results are obtained according to this invention when the silverhaloiodide is silver chloroiodide, or preferably silver bromoiodide orsilver bromochloroiodide. Advantageously, the silver haloiodide emulsionlayer or layers contains from 0.5 to 10 mole percent, and preferably 1to 6 mole percent iodide.

An especially useful emulsion arrangement consists of silver haloiodidein the red and green sensitive layers and an essentially iodide-freesilver halide, such as silver chlo ride or bromide, in the bluesensitive layer. By essentially iodide-free we mean that small amounts,e.g. up to about 0.5 mole percent, of iodide may be present in thesilver halide grains.

The emulsions can contain various chemical sensitizers, opticalsensitizers, stabilizers, speed increasing compounds, plasticizers,hardeners and coating aids, such as are described and referred to inProduct Licensing Index, Vol.- 92, December 1971, publication 9232, atparagraphs IH, V, VII, XI, XII, XV pp. 107-110. Any suitable supportmaterial can be used, such as those described in the Product LicensingIndex reference at paragraph X.

The color forming developer solutions which can be used to produce theinterlayer interimage efiects according to this invention contain asilver halide solvent. The most useful of such color forming developersolutions employ phenylenediamine and substituted derivative developingagents, such as those disclosed in Weissberger et al., US. Pat.2,548,574 issued Apr. 10, 1951; Weissberger et al., US. Pats.2,552,240-2 issued May 8, 1951; and Weissberger et al., US. Pat.2,566,271, issued Aug. 28, 1951. Typical phenylenediamine developingagents include diethyl-p-phenylenediamine hydrochloride, Z-amino-S-diethylaminotoluene monohydrochloride, 2-amino-5-(N-ethyl-N-laurylamino)-toluene, N-ethyl-N- (beta-methanesulfonamidoethyl)-4-aminoaniline, etc. The p-aminophenols and theirsubstitution products where the amino group is unsubstituted can also beused. Various other materials may be included in the developer solutionsdepending upon the particular requirements, for example, an alklai metalsulfite, carbonate, bisulfite, bromide, iodide, etc., and the thickeningagents used in viscous developer solutions such as carboxymethylcellulose, gelatin, etc. The following is a typical developer solutiongiven to illustrate but not limit the invention.

In addition to those developing agents referred to above, any of theother well known color forming developing agents can be employed toadvantage in the process of this invention.

Developer solutions containing these conventional color formingdeveloping agents are modified, according to this invention, by theaddition of a silver halide solvent to the developer formulation inorder to achieve the pro duction of the interlayer interimage effects.

The useful silver halide solvents according to this invention includethe following: ammonium hydroxide, ethylenediamine, dithiooctanediol,ethanolarnine, isopropylamine, n-butylamine,1,8-dihydroxy-3,6-dithiaoctane, as

well as others well known in the art. The silver halide.

solvents especially useful according to this invention are thethiocyanate salts such as guanidine thiocyanate, sodium thiocyanate,potassium thiocyanate, etc.

The silver halide solvents may be used in concentrations of from about0.1 to 5.0 grams/liter With a preferred range of from about 0.5 to 2.5grams/liter especially useful.

The interlayer interimage producing, iodide-containing emulsions of thisinvention can be used in a process for providing a multicolorphotographic reproduction which includes (1) developing silver images inan exposed photographic element having at least two superposedhydrophilic colloid layers containing silver halide and (2) formingdifferentially colored dye images in proportion to said silver images.For example, the iodide emulsions are highly useful in completephotographic negative processes wherein a multilayer photographicelement containing a plurality of differentially sensitized photographicsilver halide emulsion image recording layers wherein the element isgiven a first imagewise exposure, followed by a development in a colordeveloping solution containing a silver halide solvent for reducing thesilver and then removing the residual silver and silver halide wherebydye images having brighter and more saturated colors are produced.

As is known, a highly useful arrangement of light sensitive silverhalide layers for the production of negative multicolor photographicrecords comprises a support having a coated thereon, superposed lightsensitive silver halide image recording colloid layers which aresensitive, respectively, to red, green and blue radiation. Silver imagescan be developed in such layers, and dyes formed imagewise in proportionto the developed silver image. Advantageously, cyan, magenta and yellowdyes are formed in proportion to the red, green and blue layersrespectively. Such dyes can be formed in any convenient manner, such asin the conventional color processes wherein a dye image is formed havinga complementary relationship to the region of the spectrum to which thesilver halide emulsion is sensitized. The dyes that are formed accordingto this invention can be produced from any of the color formers known tothe art. By color formers we mean compounds that react with oxidizedcolor developing agents to form dyes. Suitable color formers are thecolor couplers known to the art. Examples of typical color formingcouplers are listed in the aforementioned Product Licensing Indexreference at paragraph XXH.

For example, a typical multilayer negative color film may comprise threeunits coated on a support the first unit on a support containing asilver halide emulsion image recording layer sensitized to red radiationand adapted to produce a cyan dye; a second unit comprising at least onesilver halide emulsion image recording layer sensi tized to greenradiation and adapted to produce magenta colored dye; and a third unitcomprising at least one silver halide emulsion image recording layersensitive to blue radiation and adapted to produce a yellow colored dye.Any one of such units or any two of such units, can contain the iodidecontaining silver halide emulsions of this invention. In a preferredembodiment the red and green sensitive units contain the iodide contentsilver halide. The interlayer interimage effect is achieved whether thecombination of emulsion layers provided by this invention is employed ina yellow, magenta, cyan or other colored dye producing color formingunit so long as the exposed element is developed in a color developercontaining a silver halide solvent.

This invention will be further illustrated by the following examples:

EXAMPLE 1 A mutilayer color negative print film element bearing in orderon a transparent support, a gelatino silver halide red sensitive,cyan-forming unit, a gelatin interlayer, a gelatino silver halide greensensitive, magenta-forming unit, a yellow filter layer, a gelatinosilver halide blue sensitive layer, yellow-forming unit and a gelatinovercoat layer is first prepared. The cyan and magenta forming layerscontain a silver bromoiodide emulsion of 6 mole percent iodide. Theyellow-forming layer contains a conventional silver chlorobromideemulsion. A control is prepared as described above, except that theemulsions contain only silver chloride or silver bromide. Separatesamples of these elements are then exposed to red, green or blue lightthrough a step tablet on a sensitometer. Separate samples of each ofthese elements are then given overall flash exposure with each of thetwo primary colors not used for the stepwise exposure and processed at atemperature of from 20-28" C. as follows:

Baths 1. Color develop 5. Wash 2. Stop-fix 6. Fix 3. Wash 7. Wash 4.Bleach 8. Stabilize The chemical composition of the above processingbaths is as follows:

Developer:

Water ml 1000.00 Sodium hexametaphosphate g 2.00 Sodium sulfite g 4.00Sodium carbonate H O g 20.00 Potassium Bromide g 2.00 2-amino 5diethylaminotoluene monohydrochloride g 3.00 Sodium thiocyanate g 1.00Stop-Fix Bath:

Water ml 600 Sodium thiosulfate g 240.0 Sodium sulfite, desiccated g15.0 Acetic acid, (28%) ml 48.0 Boric acid g 7.5 Potassium alum g 15.0Water to ml 1000.00 Bleach:

Water ml 1000.00 Potassium dichromate g 5.0 Potassium bromide g 20.0Potassium alum g 40.0 Fix:

Water ml '600 Sodium thiosulfate g 240.0 Sodium sulfite, desiccated g15.0 Acetic acid, (28%) ml 48.0 Boric acid g 7.5 Potassium alum g 15.0Water to ml 1000.00 Stabilizer:

Formaldehyde 37% solution ml 15 Kodak Photo-Flo concentrate ml 2.0 Waterliter 1 The processed film is then analyzed for interimage effects.Curves are plotted for magenta interimage as a function of cyan, yellowinterimage as a function of cyan, cyan interimage as a function ofmagenta and yellow interimage as a function of magenta for a flashdensity level of 2.5. The greater the density (AD) difference, thegreater the interlayer interimage eifects. The negative figures in TableI indicate the restraint in development of the various layers which is ameasure of correction for the unwanted absorptions of these layers.

The procedure of Example 1 is performed at about room temperature buthigher temperature of up to 55 C. may be used with a resultant decreasein processing time.

EXAMPLES 26 Several elements and a control element are prepared as inExample 1, except that the emulsions have silver halide contents as setforth in Table II.

TABLE H Mole Mole Mole percent percent percent halide halide Mahalide(Br/I or (Br/I) genta (Br/I) Yellow Cl/Br) 97. 5/2. 5 AgBrI 99. 5/0. 52/98 94/6 .AgBrI 97. 5/2. 5 AgClBr 2/98 94/6 AgBrI 99/1 AgClBr 2/98 99/1AgBrI 99/1 AgClBr 2/98 These elements are processed as in Example 1 withthe color developer used therein, containing 1.0 g. of the silver halidesolvent sodium thiocyanate per liter of color developer. The greater thedensity (AD) difierence the greater the interimage effect. Theinterimage effect is reported in Table HI as the difierence in densityfor a flash density of approximately 2.5.

EXAMPLES 7-12 Elements of Examples 2-6 are processed according to theprocedure of Example 1 except that 2.0 g./liter of sodium thiocyanate isemployed in the color developer formulation of Example 1. The resultinginterimage effects are listed in Table IV. Where interimage values arenot obtainable for a flash density of 2.5, values are taken at the nexthighest and next lowest flash density, so that in some instances twovalues are listed.

6 mole percent iodide that is sensitive to the red region of thespectrum, a cyan forming unit, a gelatin interlayer,

a gelatino silver bromoiodide emulsion of 6 mole percent iodide, amagenta-forming unit, a yellow filter layer, a gelatino silverbromochloride blue sensitive layer and a yellow-forming unit with agelatin overcoat. A control" is prepared as described above, except thatall three emulsions contain silver bromide. These elements are thenexposed to red, green or blue light through a step tablet on asensitometer. Separate samples of each of these elements are then givenoverall flash exposure with eachof the two primary colors not used forthe stepwise exposure and processed as in Example 1, except that thesilver halide solvent sodium thiocyanate is substituted with thefollowing silver halide solvents:

TABLE V Example: Solvent 13 Guanidine thiocyanate l4 Potassiumthiocyanate 15 Ammonium hydroxide 16 Ethylene-diamine 17Dithiooctanediol l8 Isopropylamine l9 n-Butylamine 20 Ethanolamine 211,S-dihydroxy-3,6-dithiaoctane.

In all these examples the elements containing the silver bromoiodideemulsions yield brighter and more saturated dye images with theresulting negative image being of fine quality for use as a colornegative.

The invention has been described in detail with particular reference tocertain preferred embodiments thereof, but it will be understood thatvariations and modifications can be effected within the spirit and scopeof the invention.

We claim:

1. In a process for providing interlayer interimage effects inmultilayer silver halide emulsion containing color photographic elementswhich process comprises (a) utilizing an imagewise-exposed elementcontaining from 0.510 mole percent iodide as mixed silver halide in atleast one of the silver halide emulsion image recording layers and atleast one silver halide emulsion image recording layer being essentiallyiodide free,

(b) developing said image-wise exposed element in a color developer, and

(c) removing residual silver and silver halide from said element; 7 theimprovement whichcomprises in step (b) using a color developer whichcontains silver halide solvent, whereby a color negative is obtainedhaving improved interimage characteristics.

2. The process for providing improved photographic interimage effects asdefined in claim 1 wherein the element contains a first emulsion imagerecording layer TABLE IV Magenta Yellow Cyan Yellow interimageinteriniage interimage inter-image Element Function of Function of ofFunction of Function of magenta magenta Example example cyan (AD) cyan(AD) (AD) (AD) Control 0. 0 0. 0 0. 0 0. 0 1 0 48/-0 50 0.54 0. 77l-0.66 -0. 98/1. 21 2 +0. 29 0. 58l-0. 67 3 0. l6 0. 29 -0. 45l-0. 72 0.62l-0. 72 4 0. 20/0. 45 0. 50/0. 43 5 0. 19/0. 35 '0. 26/-0. 21 6 0.(WI-0. 10 -0. 24 0. 48/(). 28 0. 27/-0. 23

EXAMPLES 13-21 Several multilayer color negative elements are prepared.To a transparent polyethylene terephthalate support is apsensitive toblue radiation said layer also containing a color former that forms ayellow colored dye upon color developement and a second emulsion imagerecording plied, in order, a gelatino silver bromoiodide emulsion of 75layer spectrally sensitived to red radiation and which contains a colorformer that forms a cyan colored dye 'upon color development.

3. The process for providing improved photographic interimage effects asdefined in claim 11 wherein the element contains a first emulsion imagerecording layer sensitive to blue radiation; said layer also containinga color former that forms a yellow colored dye upon color developmentand a second emulsion image recording layer spectrally sensitized togreen radiation and which contains a color former that forms a magentacolored dye upon color development.

4. The process for providing improved photographic interimage effects asdefined in claim 1 wherein the element contains a first emulsion imagerecording layer spectrally sensitized to red radiation said layer alsocontaining a color former that forms a cyan colored dye upon colordevelopment and a second emulsion image recording layer spectrallysensitized to green radiation and which contains a color former thatforms a magenta colored dye upon color development and a third emulsionimage recording layer sensitive to blue radiation and which contains acolor former that forms a yellow colored dye upon color development.

5. The process according to claim 4 wherein the red sensitive emulsionlayer contains 0.5-10 mole percent iodide as mixed silver halide.

6. The process according to claim 4 wherein the green sensitive emulsionlayer contains 0.5-10 mole percent iodide as mixed silver halide.

7. The process according to claim 4 wherein both the green andredsensitive emulsion layers contain 0.5-10 mole percent iodide as mixedsilver halide.

8. The process according to claim 1 wherein the color developer solutioncontains a phenylenediamine developing agent.

9. The process of claim 1 wherein the silver halide solvent is athiocyanate salt.

10. The process of claim 1 wherein the silver halide. solvent content ofthe color developer solution is from about 0.5 to 2.5 grams per liter ofcolor developer solution.

References Cited UNITED STATES PATENTS 3,536,487 10/1970 Graham 96223,713,828 1/1973 Hayashi et al. 96-74 RONALD H. SMITH, Primary ExaminerA. T. SURO PICO, Assistant Examiner US. Cl. X.R. 9666 R, 74

mg UNITED STATES PATENT OFFICE CERTIFICATE OF CORRECTION Pacent No.3332,17 Dated August 27,- 197A Inventor(s) Hobson J. Bello, Jr. andAlbert C. Smith, Jr;

It is certified that error appears in the above-identified patent andthat said Letrers Patent are hereby corrected as shown below:

Column 7, line A, "claim 11" Y should read -claim 1--.

Signed and sealed this 10th day of- December 1974.

(SEAL) Attest GIBSON JR. 0. MARSHALL DANN MCCOY M Commissioner'ofPatents Attesting Officer

